1. Field of the Invention
This invention relates to a device for loading or unloading a magnetic disc pack and, in particular, to a device for loading or unloading a magnetic disc pack used in a magnetic recorder and/or reproducer for an electronic camera and the like and incorporating therein a magnetic disc capable of magnetically recording still image information and the like.
2. Description of the Prior Art
Recently, there has been developed an electronic still camera system which comprises a combination of an image pickup device such as a charge coupled device (CCD), an image pickup tube or the like and a recording device using as its recording medium an inexpensive magnetic disc having a comparatively higher memory capacity, and in which a subject is still-photographed electronically and recorded into the magnetic disc while it is rotating and reproduction of an image recorded therein is carried out by separately arranged means such as a television receiver, a printer or the like.
The magnetic disc employed in the above-described system is generally used in the form of a magnetic disc pack. Specifically, in the magnetic disc pack, there is included a rotatable magnetic disc capable of magnetically recording therein still image information or the like, and the magnetic disc pack is mounted into a magnetic recording device incorporated in an electronic camera or into a magnetic reproduction device which is arranged integrally with or separately from the recording device before the magnetic disc pack can be actually used.
Conventionally, there has been known a so-called slot-in power loading device as a device for loading or unloading the magnetic disc pack. The slot-in power loading device is arranged such that, when the magnetic disc pack is inserted into and stored in a holder movable supported by a main body of a magnetic recording/reproducing apparatus via an insertion opening formed in a front panel of the apparatus main body, it can move the holder automatically by means of a necessary route to thereby guide the magnetic disc of the magnetic disc pack within the holder to a rotary drive shaft in the apparatus main body for mounting thereto.
In the above-mentioned magnetic disc pack loading/unloading device, there is provided an eject lever within the holder which biases the magnetic disc pack in a direction to discharge it, and, when loading, the magnetic disc pack is inserted into the holder against the biasing force of the eject lever and is secured therein. However, since the magnetic disc pack is formed light in weight, if the holding of the magnetic disc pack within the holder when unloading it is released, then the magnetic disc pack is flies forcefully from the holder by the biasing force of the eject lever. This means that the slot-in power loading device is inconvenient to handle.
Also, in the conventional magnetic disc pack loading/unloading device, when the magnetic disc pack is held within the holder, then the eject lever becomes locked. Thus, when the locking of the eject lever is released in connection with the positional displacements of the holder caused by an electric driving operation, if the eject lever is once locked, it is not easy to take out the magnetic disc pack while power is turned off due to an accident or the like. Since the shutter of the magnetic disc pack is open within the holder, it is not desired to leave it in this condition for a long peiod of time in view of dust prevention.
Further, in the conventional magnetic disc pack loading/unloading device, there is a possibility that although one magnetic disc pack is already stored in the holder, another magnetic disc pack may be inserted in error thereinto from the insertion opening thereof. The double insertion of the two magnetic disc packs may damage the important parts such as a magnetic head and the like.
In addition, in the conventional magnetic disc pack loading/unloading device, while the magnetic recording or reproducing operation is being performed, if the power supply is cut off in error, then it is impossible to unload the magnetic disc pack and thus the magnetic head is left in a state for a long time in which it is in contact with the magnetic disc. If the magnetic disc is left in this condition for a long period of time, then there is produced a pressure sign or the like therein, resulting in a dropout or the like.